### Answer To extract values from your MCP tool response, you can use the response variables feature when configuring your MCP tool. [(1) ]() For a response like:

json
{
  "availableDates": [
    {"dateFrom": "2025-12-15T14:00:00.000Z", "dateTo": "2025-12-15T15:00:00.000Z"},
    ...
  ]
}

You would set response variables to extract values and save them as dynamic variables for use later in the conversation. For example, you can reference a value like

{{available_dates}}

later in the flow. Important caveat: There's a known issue where MCP tools may return stringified responses (e.g.,

"{\"customer_id\": 12345}"

instead of

{"customer_id":"6229"}

) , which can cause variables to not be extracted properly. [(2) ]() If you're experiencing issues with variable extraction, check your MCP server's response format—it may be returning a stringified JSON rather than a proper JSON object.

​ To learn more, see the sources I considered: [[1] MCP](https://docs.retellai.com/build/single-multi-prompt/mcp) [[2] mcp tool variables not extracted](https://discord.com/channels/1186424376300679209/1426340769924382791) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.